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Old 14th Mar 2019, 9:59 pm   #22
PaulM
Hexode
 
Join Date: Nov 2006
Location: Near Lincoln, UK.
Posts: 481
Default Re: CCD camera history

The difficulty here is not the consumer/broadcast applications which surfaced 'on the record', it's the likely untold story of military R&D. If something is a game changer from a technological perspective for military applications, it's 'sat on'. No patents will appear and the general public will know nothing until it (eventually) breaks through. Primary sources for CCD technology in this field will be hard to come by, even now. The period we're talking about is the height of the Cold War and things are still a bit twitchy in the history department!

At the risk of going OT, I can tell a story which illustrates what this *could* lead to. Over 10 years ago now, probably nearer 12 or 13, I was lucky enough to be involved in some deep R&D which took me to St Petersburg on many occasions. Cutting a long story short, I was privileged to visit the TV museum there - no, not the public Post and Telecommunications one, but I did go there too. This one was 'private' and documented all manner of broadcast and space oriented TV work. It was fascinating, and no more so when I received an invitation to go down the corridor to look at something they didn't normally show visitors. As the huge steel door clanged shut behind us, I could make out something the size of a single-decker bus. The light clicked-on and there it was - a Soviet era 'spy satellite' from the late 60s. The technology was explained as using 6" vidicons (yes, 6") and there were four of them, each with a lens the size of an old round-type dustbin. The cameras resolved 4,000 lines and fed a still frame back to the ground in a second or two to be printed out on an electron-beam recorder (also on show) back at the ground station. Impressive? You bet. It was further explained to me that the Soviet thinking was that the US 'equivalent' was flawed, in that it was a relatively low resolution line array camera (technology not described), which produced high resolution pictures using the motion of the satellite as the 'frame scan'. This took well over three minutes per frame and my hosts pointed out that an ICBM would be up and away well before their camera had even seen it! The Soviet scheme was near real-time and, it was claimed gave them the edge. It was admitted that the vidicons didn't always give a 'good picture', but why was not elaborated on.

Now, the USA probably knew all of this and could have gone the vidicon route (and perhaps did), but a CCD line array camera could have given them the edge, especially if the 'vertical' scanning rate could be increased using a mechanical scanner. Line arrays are much simpler than frame arrays, and apart from pixel by pixel normalisation, could have been created with 60s technology.

The above is, admittedly, speculation, but that's where you are with much of the military technology from that period. I suspect, but would need to prove (somehow), that the origins of CCDs are older than is 'known', but it would take some digging to prove it. My suspicion would be that this history is still 'secret' (even though the technology is common knowledge and much improved.

This takes us back to primary sources. Patents are one example, but you need to go deeper to see if there's anything pre-dating that public manifestation.

Shoot me down, but as a qualified historian (and engineer), this is the kind of thing I'm looking for all the time. The Internet is simply not a good enough resource for things such as this.

Best regards,

Paul M
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